# US 2025/0085463 A1 · Color Coatings with Two-Layer Thin-Film Interference Filter

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2025/0085463 A1
- Document ID: US20250085463A1
- Status: Published application
- Kind: A1
- Application number: 18/523,605
- Filed: 2023-11-29
- Published: 2025-03-13
- Earliest claimed: 2023-09-07
- Assignees: Apple Inc.
- Applicants: Apple Inc.
- Inventors: Brian S Tryon; Jozef M Matlak; Ziqing Duan; Yi Zhou; Di Fan; Donghai Yu
- Web page: https://patentgrep.com/patent/US20250085463A1

## CPC

- G02B 5/286: {having four or fewer layers, e.g. for achieving a colour effect}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

An electronic device may be provided with conductive structures such as conductive housing structures. A visible-light-reflecting coating may be formed on the conductive structures. The coating may have adhesion and transition layers, an opaque coloring layer on the adhesion and transition layers, and a two-layer thin-film interference filter on the opaque coloring layer. The two-layer thin-film interference filter may an uppermost diamond-like carbon (DLC) or CrSiCN layer and a lowermost SiCrCN layer. The coating may exhibit a dark blue or black color that has a relatively uniform visual response even when the underlying conductive structures have a three-dimensional shape.

## Claims

### Claim 1

Apparatus comprising:
a conductive substrate; and
a coating on the conductive substrate and having a color, the coating comprising:
adhesion and transition layers, and
a two-layer thin-film interference filter on the adhesion and transition layers, wherein the two-layer thin-film interference filter comprises a CrSiCN layer.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the CrSiCN layer is a lowermost layer of the two-layer thin-film interference filter.

### Claim 3 (depends on 2)

The apparatus of claim 2, wherein the two-layer thin-film interference filter further comprises an additional CrSiCN layer on the CrSiCN layer.

### Claim 4 (depends on 3)

The apparatus of claim 3, wherein the coating further comprises an opaque CrSiN layer between the adhesion and transition layers and the CrSiCN layer.

### Claim 5 (depends on 4)

The apparatus of claim 4, wherein the adhesion and transition layers comprise a Cr seed layer on the substrate and a CrSiN transition layer between the Cr seed layer and the opaque CrSiN layer.

### Claim 6 (depends on 3)

The apparatus of claim 3, wherein the additional CrSiCN layer is thicker than the CrSiCN layer.

### Claim 7 (depends on 6)

The apparatus of claim 6, wherein the additional CrSiCN layer is more than 60 nm thick and the CrSiCN layer is less than 50 nm thick.

### Claim 8 (depends on 3)

The apparatus of claim 3, wherein an atomic percentage of Cr atoms in the additional CrSiCN layer is less than 30%, an atomic percentage of Si atoms in the additional CrSiCN layer is greater than 30%, and an atomic percentage of C atoms in the additional CrSiCN layer is less than 30%.

### Claim 9 (depends on 8)

The apparatus of claim 8, wherein an atomic percentage of Cr atoms in the CrSiCN layer is greater than 25%, an atomic percentage of Si atoms in the CrSiCN layer is less than 40%, and an atomic percentage of C atoms in the additional CrSiCN layer is greater than 20%.

### Claim 10 (depends on 2)

The apparatus of claim 2, wherein the two-layer thin-film interference filter further comprises a diamond-like carbon (DLC) layer on the CrSiCN layer.

### Claim 11 (depends on 10)

The apparatus of claim 10, wherein the CrSiCN layer is thicker than the DLC layer.

### Claim 12 (depends on 11)

The apparatus of claim 11, wherein the CrSiCN layer is more than 200 nm thick and the DLC layer is less than 100 nm thick.

### Claim 13 (depends on 10)

The apparatus of claim 10, further comprising an opaque layer between the adhesion and transition layers and the CrSiCN layer, the opaque layer comprising carbon, silicon, and nitrogen.

### Claim 14 (depends on 1)

The apparatus of claim 1 wherein, at a location of maximum thickness and a viewing angle of zero degrees relative to a normal axis of the coating, the coating has an L* value greater than 30, an a* value between −10 and 10, and a b* value between −20 and 0.

### Claim 15

An electronic device comprising:
a conductive structure; and
a coating on the conductive structure and having a color, the coating comprising:
adhesion and transition layers, and
a thin-film interference filter on the adhesion and transition layers, wherein the thin-film interference filter has an uppermost layer that includes CrSiCN and has a lowermost layer that includes CrSiCN.

### Claim 16 (depends on 15)

The electronic device of claim 15, wherein the uppermost layer directly contacts the lowermost layer of the thin-film interference filter.

### Claim 17 (depends on 15)

The electronic device of claim 15, the coating further comprising:
an opaque layer between the thin-film interference filter and the adhesion and transition layers, the opaque layer comprising CrSiN.

### Claim 18

An electronic device comprising:
a conductive structure; and
a coating on the conductive structure and having a color, the coating comprising:
adhesion and transition layers, and
a thin-film interference filter on the adhesion and transition layers, wherein the thin-film interference filter has a first layer that includes diamond-like carbon (DLC) and has a second layer that includes CrSiCN.

### Claim 19 (depends on 18)

The electronic device of claim 18, wherein the second layer is interposed between the first layer and the adhesion and transition layers.

### Claim 20 (depends on 18)

The electronic device of claim 18, the coating further comprising:
an opaque layer between the thin-film interference filter and the adhesion and transition layers, the opaque layer comprising CrSiCN.